Throw early when a non-stream-context resource is passed to libxml_set_streams_context() (#14279)

Author: nielsdos

NEWS

@@ -98,6 +98,8 @@ PHP                                                                        NEWS
 
 - LibXML:
   . Added LIBXML_RECOVER constant. (nielsdos)
+  . libxml_set_streams_context() now throws immediately on an invalid context
+    instead of at the use-site. (nielsdos)
 
 - MBString:
   . Added mb_trim, mb_ltrim and mb_rtrim. (Yuya Hamada)

UPGRADING

@@ -383,6 +383,11 @@ PHP 8.4 UPGRADE NOTES
   . ResourceBundle::get() now has a tentative return type of:
     ResourceBundle|array|string|int|null
 
+- LibXML:
+  . libxml_set_streams_context() now immediately throws a TypeError when a
+    non-stream-context resource is passed to the function, instead of throwing
+    later when the stream context is used.
+
 - MBString:
   . The behavior of mb_strcut is more consistent now on invalid UTF-8 and UTF-16
     strings. (For valid UTF-8 and UTF-16 strings, there is no change.)

ext/libxml/libxml.c

@@ -1049,10 +1049,12 @@ PHP_FUNCTION(libxml_set_streams_context)
 		Z_PARAM_RESOURCE(arg)
 	ZEND_PARSE_PARAMETERS_END();
 
-	if (!Z_ISUNDEF(LIBXML(stream_context))) {
-		zval_ptr_dtor(&LIBXML(stream_context));
+	if (php_stream_context_from_zval(arg, true) != NULL) {
+		if (!Z_ISUNDEF(LIBXML(stream_context))) {
+			zval_ptr_dtor(&LIBXML(stream_context));
+		}
+		ZVAL_COPY(&LIBXML(stream_context), arg);
 	}
-	ZVAL_COPY(&LIBXML(stream_context), arg);
 }
 /* }}} */
 

ext/libxml/tests/bug63389.phpt

@@ -4,15 +4,20 @@ Bug #63389 (Missing context check on libxml_set_streams_context() causes memleak
 libxml
 --FILE--
 <?php
-$fp = fopen("php://input", "r");
-libxml_set_streams_context($fp);
 try {
     libxml_set_streams_context("a");
 } catch (TypeError $e) {
     echo $e->getMessage(), "\n";
 }
+$fp = fopen("php://input", "r");
+try {
+    libxml_set_streams_context($fp);
+} catch (TypeError $e) {
+    echo $e->getMessage(), "\n";
+}
 echo "okey";
 ?>
 --EXPECT--
 libxml_set_streams_context(): Argument #1 ($context) must be of type resource, string given
+libxml_set_streams_context(): supplied resource is not a valid Stream-Context resource
 okey